Animal feed composition and method of using same



, swine and particularly early weaned pigs.

of the other tetracycline antibiotics.

3,185,573 ANIMAL FEED COMPOSITION AND METHOD OF USING SAME Max J.Harvey, Trenton, N.J., assignor to American Cyanamid Company, Stamford,Conn., a corporation of Maine No Drawing. Filed Oct. 29, 1962, Ser. No.233,950

g 14 Claims. (Cl. 99-2) This invention relates to an animal feedcomposition effective in accelerating the growthrate of animals and moreparticularly is concerned with a novel combination of a tetracyclineantibiotic, a sulfon'amide such as sulfamethazine orsulfaethoxypyridazine, and penicillin as an animal feed additivecomposition which significantly enhances the growth rate of animals suchas poultry and In the past, combinations of a tetracycline antibiotic,such. as chlortetracycline, and penicillin have been used in animalfeeds as growth promoters. The use of sulfamethazine andsulfaethoxypyridazine, on the other hand, has been limited to achemotherapeutic use in the" treatment of livestock diseases.He'retofore, these compounds have been administered intherapeuticdosesas injectables, capsules, or tablets for thetreatment of a specificdisease condition because high-level medication-in the feed or drinkingwater. has been usually unpalatable to animals such as swine and thelike,

It has been discovered that the novel combination of a tetracyclineantibiotic, sulfamethazine or sulfaethoxypyridazine and penicillin,produces an accelerated rate of growth which is Wholly unexpected fromthat observed heretofore.

Thus in accordance with the present invention low concentrations ofsulfamethazine or sulfaethoxypyridazine,

United States Patent a tetracycline antibiotic and an antibiotic feedsupplement, such as procaine penicillin, when added to an animal feedaid in increasing growth rate, improve feed efliciency, 1 reduce lossesassociated with bacterial enteritis, cervical abscesses, atrophicrhinitis, and in the suppression of intercurrent or secondary infectionsof the diseases indicated during periods of stress, such as weaning,castration, vaccination, high temperature, and moving.

The present invention has the advantage that the growth rate ofnon-ruminants, such as poultry and swine and especially weanling pigs,is significantly increased; that diseases such as those rnentionedaboveare effectively controlled and that feed conversion rates are noticeablyenhanced.

Any of the commercially available and commonly used tetracyclineantibiotics, such as tetracycline,-chlortetracycline, oxytetracycline,demethylchlortetracycline, and

ferred because of its-already wideacceptance asan animal feed additiveof choice and ismore effective than some I the optimum amountbeihgaboutylQO grams/ton of feed.

f The sulfonamides are present to theextent of from about 10 to about300 gramsper ton of feed and. preferably about 100 grams per ton'offeed. ,Penicillin, usually in the forrn of a salt such as procainepenicillin, ispresent 3,185,573 Patented May 25, 1965 to the extent offrom about 5 to about 150 grams per ton of feed and preferably about 50grams/ton of feed.

The invention will be described in greater detail in conjunction withthe following specific examples.

EXAMPLE 1 In this experiment 30 pigs of essentially equal weight weredivided into 6 equal groups. Infected and noninfected control groupswere established. Two noninfected control groups were placed on astandard, starter,

non-medicated pig diet formulated as follows:

Standard pig diet Profactor 10 lbs 2 Zinc sulphate (gms.)

' Man/lb Riboflavin 2,000

Pantothenic acid 4,000

. Niacin 9,000

Choline chloride Folic acid 5 Vitamin B12 Base consists of meals andsolubles clilortetracycline.

The second control groups were infected with the test organism,Salmonella choleraesuis var. kunzendorf, and placed on the samenon-medicated, starter pig diet.

The'final test groups were infected with the same organism and wereplaced on the above-mentioned standard diet which had been medicatedwith gms./ton of chlortetracycline, 100 gms./ton of sulfamethazine, and49. gms./ ton of penicillin.

. The data which appear in Table 1 below represent indivdual weight gaindata for pigs in replicate groups during aIthree-week, post-infectionperiod after infection 1 the likemay be used. Chlortetracycline,however, is pre-. 1

with the organism. Medication with 100 gms./ton of chlortetracycline,100 gms./ ton of suliamethazine, and 49 gms./ ton of penicillin in thefed was begun two days prior to: infection and continued for theduration of the trial.

Weight gain data commences from the day of infection and Was collectedweekly for a period of three weeks at which time the trial wasterminated;

- fection by Salmonella cholemesuis var. kunzendorf of the These dataclearly illustrate the effectiveness against incombination ofchlortetracycline, 'sulfamethazine', and penicillin when employed at lowlevels and administered to-swine in feed.

[Body weight gains (lbs.) of pigs infected with Salmonella cholcraesulsvar. ham. and medicated with 100 gins/ton chlortetracyclinc 100 gmsJtonsulfamethazine, 49 gms./ton penicillin in the feed and pigs onnon-medicated feeds when infected and non-infected Original Weight gain(lbs.)/pig/group/week post-infection Group Treatment weight of Finalweight separate pigs 1st week 2nd week 3rd week Total 47. 5 15. 5 13. 51;. g g 24. 37. 10. 5 10.0 5. 0 1 Nmmmected, 40. 0 10. 5 10. 0 12. 5 33.0 73. c Wed 37. o 5. 5 8.0 11.0 24. 5 61.5 35. 5 7.0 7. 5 9. 5 24. 0 59.5

Average..- 9. 8 9 8 11.5 31. 1 Total 197. 5 353. 0

. 43. 0 O. 5 .5 0 1A N n4nfecte nmmedi' a9. 0 12. 0 11.0 13. 5 36.5 75.5 0 e 3s. 0 16. 5 12. 5 13. 0 42. 0 80.0 34.0 9. 0 10.5 10.5 30.0 64. 0

Avera e 11 6 11. 5 12 2 35.3 Total- 196. 0 372. 5

49.0 5. 5D 38. 0 2 Infected; n0n-medi0ated 40. 0 0 2. 0 6 0 8.0 48. 035. 0 0 6. 0 6 5 12.5 47. 5 36. 5 2. 0 0. 5 4 5 3.0 39. 5

Average 1. 9 2. 8 5. 7 7. 8 Total 198. 5 135. 0

41 0 --1. 0 1. 0 0 0 41. 0 41 0 *3. 5D 2A Infected; n011-mcdicated 39 03. 0 4. 5 11.5 13.0 52.0 39 0 4. 0 8. 0 D 38 0 1.0 1.0 4. 0 --4. 0 34.0

Average 2. 5 0. 13 2. 5 3. 0 Total 198. 0 127. 0

3 Infected, medicated feed, 48; 5 3. 5 l1. 0 13.0 27. 5 76, 0

100 gmsJton chlortetra- 38. 5 1. 5D cycline, 100 gms./ton sul- 38. 0 9.0 10. 0 9. 5 28. 5 6G. 5 faniethazine, 49 gms./t0n 36. 0 7. 0 11. 0 11.0 29. 0 65. 0 penicillin. 36. 5 6.0 11.5 11.0 28. 5 65.0

Average 5 4 10.9 11 1 28.3 Total 197. 5 272. 5

3A Infected, medicated feed, 45. 0 4. 5 14.0 13.5 32. O 77. 0 100gins/ton chlortetra- 41. 0 1. 5 9. 5 11. O 22. 0 63. 0 cycline, 100gins/ton sul- 40. 0 6. 0 11. 0 11. 0 28. 0 68. 0 famethazine, 50 gmsJton39. 0 10. 0 16. 0 14. 5 40. 5 79. 5 penicillin. 36.0 --1 0 4. 5 13.517.0 53. 0

Aver- 7 '1 age 4. 2 11 0 12.7 27. 9 Total.-- 201- 0 340. 5

D =Died between last indicated weigh day and following one,

EXAMPLE 2 In this experiment 30 mixed, Hampshire-Yorkshire 6Ocross-swine ranging from 2.5 to 3.0 months of age and weighing 33.5 to49.5 pounds were employed. 30 pigs were distributed, by weight, among 6equal groups resulting in l-infected, control group; l-non-infected,control group; and 4-infected, treatment groups.

Feed consumption and weight gains were recorded for the seven-day,pre-infection period and at seven-day intervals up to twenty-one dayspost-infection.

Five days before the day of infection with Salmonella chloreraesuis var.kunz., all pigs were vaccinated for hog cholera so that the height ofthe reaction to the vaccination would occur at about the time of theinduced infection.

Feed for each group of 4 infected pigs was prepared as a batch at therate of 0.5 lb. of feed per pig which'contained approximately 25 cc. ofthe culture Salmonella choleraesuis var. kunzendorf.

All pigs were held off feed for 18 hours prior to being offered theinfected feed. The infected feed was then provided and the pigs in agiven group allowed free access until the feed was consumed. Normal feedwas returned to the feeders at this time. Daily observations were madeon all groups following the feeding of the infected feed.

Feed consumption data show that gms./ ton chlortetracycline, 100gms./ton sulfamethazine, and 50 gms./ ton penicillin in the feed (group3) during the pre-infected week was a definite aid to the pigs duringthe stress period produced by the hog cholera vaccination. This groupgained 73% more than the next nearest group Although there are someerraticffluctuationsin feed consumption and weight gains during thepost-infection period in all groups, asignificant observation appear sduring the first week post-infection. The three treated, in-

fected groups (groups 3, 4 and 6") and the non-infected,

control group (group 1) I gained more w eight and consumed more feedthan the two infectedcontrol "groups 16th day of the triaLall pigs werevaccinated for erysip- I elas.

The pigs of this experiment ranged in weight from 10 to 16 pounds, withan average of 13 pounds. There was days difference in age from theyoungest to the oldest pigs.

(groups 2 and 5). The feed conversion ratio for this same period showsthat the two treated, infected groups equalled or out performed thenon-infected, control group.

Total weight gains and feed consumption for the entire twenty-eight daytrial revealed that the treated groups out performed the two infected,control groups (groups 2 1 p and 5) and the non-infected, control group(group 1).

Group 3 (medicated diet for 28 consecutive days) had the highest totalgain and feed consumption. Feed confeed conversion. below.

The treatment groups were established as set forth below. A standard,starter pig diet, as in Example 1, was used and medicated with one ormore of the active ingredients chlortetracycline, sulfarnethazine, andpenicillin.

TREATMENT GROUPS Groups; 1 2 a 4 l 5- i 6 i 7 sChlortetracyoline;grns./t0n o *0 o 0 100 100 100 '100Sulfarnethazine,gms./ton. 0 0 100 100 0 0 100 100 Penicillin, grns./ton-0 49 0 49 0 49 0 49 From the data: reproduced in Table below, it can bereadily seen thatthe combination of chlortetracycline, sulfarhethazineand penicillin improved-average daily gains I Tiz' ble 2 [Feedconsumption, weight gains (pounds) and feed conversion] Non -infectedInfected Infected; I Infected Infected Infected control controlmedicated rnedioatmi control medicated standard diet -standard dietdiet, 28 days diet, 21 days standard diet diet, 21 days 8. 34 17.0 4.936. 61 8. 30 10.11 First Week post-infection: V

Total ht 285.0 246 .5 1 801.0 303.0 246.0 283.0 7

147 141 203.5 185.5 147 182.5 a 302 319 431 414. 0 345 415. 0Avejgain/pig 29. 4 28. 2 40. 7 37. 1 29. 4 i 36. 5 Feed/ ain 2.05 2. 26'2.12 2. 23 2.35 2. 27 Total, entire period: 1 4

1;; 1 gain 1 158.5 146.0 226.0 198.5 157.0 191.0 Ave /gajn/pig 51.7,29.2 45.2 32.7 31.4 38.2 reed 398.0 404.0 542.0 500:0 428.0 501.0Feed/min 2.51 2. 77 2. 40 2. 52 2. 73 2. 62

some; 1 a

One hundred and sirgty 3 =week old pigs were weaned andcpl'accd in Sexperimental treatment groups? The groups" were established equally bysex, weight, and

quality of pig accordingto a random set of ti-numbers.

The house was heated to a temperature of.55 degrees. The pigs were onfull feed throughout the trial. The

animals were Weighed individually every two weeks.

0n the secondda'y of thet'rial, the male pigs were cas- 78% with an 11%savings in feed when compared to negative controls; Average daily gainswere .87 and .49 for the combination of the 3 drugs and control,respectively. chlortetracyclineincreased daily gains 43%. The

sulfamethazine-pencillin was no more eflective. in growth promotion thanpenicillin alone.- However, the chlor- 'tetracycline-sultamethazinecombination increased gains ";l51- with a;5% savings'in feed. This wasan 8% im- 7 trated. Two pigs died as a result of castrations. On theprovement in growth rate over chlortetracycline along. 7 j

Table 3 Groups 1 2 3 4 5 6 7 8 Chlortetraeyeline gms/ton 0 0 o 100 100100 100 Sulfamethazine gms./ton 0 0 100 100 0 0 100 100 Penicillingms./ton. 0 49 0 49 9 49 0 49 No. pigs started. 20 20 20 20 20 20 20 20De hs 0 1 0 0 1 0 2 2 Avg. pig weights:

nitial 13. 2 13. 1 13. 1 13. 2 13.2 13. 1 13. 0 13. 1 After 14 days 15.4 17. 0 16. 4 l8. 2 18. 0 l6. 17. 6 18. 8 After 28 days. 21. 4 24. 4 24.5 26. 7 27. 9 25. 3 27.8 32. 0 After 42 days 33. 8 39. 8 37. 1 39. 0 43.1 39. 3 43. 8 49. 9 Aitrgl daily gains pereent=pereent con- 1st 14 days8. 37 2. 14 2.48 1. 63 2.11 2. 50 2.14 1. 87 211d 14 days 2. 01 2. 11 1.93 1. 91 1. 90 1. 89 1. 80 1. 59 To date 28 days 2. 37 2.12 2.09 1.81 1. 97 2.06 1. 91 1. 67 3rd 14 days 1. 88 1. 94 2. 18 2. 51 1. 89 2.2. 04 2. 03 Total 42 days 2.08 2. 02 2. 13 2. 14 1. 93 2. 14 1. 98 1.85Avg. daily teed, lbs.:

(1 .52 .60 .59 .58 .71 .61 .71 .73 87 1. 11 1. 11 1. 17 1. 35 1. 19 1.32 1. 50 69 85 85 88 1. 02 90 1. 02 1. 12 1. 68 2. 14 1. 96 2. 20 2. 062. 20 2. 35 2. 60 Total 42 days 1. 02 1. 27 1. 22 1. 32 1. 36 1. 33 1.46 1. 61

EXAMPLE 4 3O EXAMPLE 5 To establish the eliect of introducing into thefeed of weanling pigs a combination of chlortetracycline, sulfamethazineand penicillin at very low levels, the following experiment wasundertaken.

Thirty weanling pigs weighing from about 31 to 36 lbs. each, weredivided into six equal groups. Initial weights were recorded and thepigs were placed in pens and permitted to feed and drink ad libitum onthe diet provided. A standard, starter pig diet as in Example 1 wasemployed to which was added the particular levels of chlortetracycline,sulfamethazine, and penicillin set forth below. Weights of each of thepigs were recorded at two week intervals and at the end of 98 days theexperiment was terminated. From the results obtained, it is clearlyevident that with levels of chlortetracycline and sulfamethazine as lowas 10 gms./ton of feed and 5 gms. of penicillin per ton of feed, growthpromotion is noticeably enhanced. At levels as low as 1.25, 1.25 and 6.3gms./ton of the respective ingredients mentioned above, there is anapparent depression in growth rate. The data obtained are shown in Table4 below.

Table 4 Chlortetraeycline, gm./

ton 0 1. 10 20 40 Suliamethazine, gm./ton O 1. 25 10 20 30 40Penicillin, g1n./ton 0 0. 63 5 10 15 20 Pigs per groupreplieated 5 5 5 55 5 Average weights:

I 'tial 32. 5 33. 7 34. 3 32.6 31. 0 36. 2 46. 6 47. 0 52. 4 48. 3 46. 155. 1 64. 3 66. 0 75. 1 69. 1 66. 9 77. 1 82. 5 85. 5 96. 9 92. 0 87. 8100. 0 100.0 102. 6 118. 1 114. 6 107. 7 121. 5 After 5th 14 days. 125.1124. 0 144. 9 142. 7 135.0 149. 1 After 6th 14 days 153. 6 149. 2 172. 6170. 5 161. 8 179. 5 After 7th 14 days".-. 176. 5 167. 2 193. 4 194. 4184. 6 201. 5 Average daily gain:

After 1st 14 days 1.01 0.95 1.29 1.12 1.08 1. After 2nd 14 days"--- 1.26 1.36 1. 63 1. 49 1.49 1. 57 After 3rd 14 days"--. 1. 30 1. 39 1.56 1. 64 1. 50 1. 64 After 4th 14 days 1. 25 1. 22 1. 52 1. 62 1. 42 1.54 After 5th 14 days 1. 80 1. 53 1. 92 2.01 1. 95 1. 97 After 6th 14days..." 2. 04 1. 80 1. 98 1. 99 1.92 2.17 After 7th 14 days..." 1.64 1. 29 1.49 1. 71 1. 63 1. 57

Average 1. 47 1. 36 1. 63 1. 65 1. 57 1. 69

7 While low-level combinations of chlortetracycline, sulfamethazine andpenicillin have been found to be extremely effective as growth promotersin early weaned pigs as shown in Example 4, such combinations have shownonly limited effect in the promotion of growth of chickens. This isevidenced by the following experiment in which 4,800 chicks were dividedinto 48 groups of 100. This experiment was run in two parts. In eachpart, 12 control groups were fed on a standard broiler feed formulatedas follows:

STANDARD CHICK BROILER-FEED DIET Pounds Cornmeal 1090 Dehydrated alfalfameal, 20% 40 Meat and bone scrap, 50% Soybean meal, 50% 425 Manhadenfish meal, 60% 100 Corn gluten meal 100 Feather meal 20 Animal andvegetable fat Distillers solubles 20 Salt 7v Limestone (calcite flour at35.7%) 9 No added phos. Premix (vitamin-mineral) 10 Coccidiostat 2 Total2003 CALCULATED ANALYSIS Protein, percent 23.3 Fat, percent 9.18 Fiber,percent 3.18 Calcium, percent 0.93 Phosphorus, percent 0.64 Ash, percent4.18 Calories/pound (productive energy) 1063 Calorie-protein ratio=45:1.

' the average weight of the control groups was 746 lbs.

and the average Weight of the medicated groups was 797 lbs. In part two,the average weight of the control groups was 767 lbs. and the averageweight of the medicated test groups was 784 lbs.

Table 5.--Chick treatments PART ONE 7 Control ASP 250 gins/ton ReplicateWt. F.E. Mort Wt. F.E. Mort.

766 1. 37 5. 43 828 1. 24 3. 10 748 1. 39 3. 10 497 1. 31 2. 32 756 1.38 3. 10 801 V 1. 31 0. 78 773 1. 25 0.78 780 t 1. 36 1. 57 720 1. 38 3.79 809' 1.33 0.78 726 1. 37 2. 32 797 1. 31 0. 78 750 1. 33 1. 52 808 1.30 3. 10 750 1. 35 0. 78 770 1. 28 2. 32 .734 1. 35 1. 55 760 1. 31 1.55 723 1. 35 0. 78 816 1. 29 3. 10 744 V 1. 32 3. 10 795 1. 30 1. 55764 1. 37 1. 55 801 1. 29 0. 78 Average percent 746 1. 35 797 1. 30

ontr 100 107 PART TWO Control 1 ASP 250 ton Replicate V l Wt. F.1'J.Mort. Wt. En. Mart.

800 1. 37 a 0. 770 1. 37" 0. 65 752 1. 42 0. 0 790 1. 32 0. 65 800 1.36 1. 31 765 1. 41 1. 31 755 1. 50 0. 65 762 V 1. 42 0. 65 762 1. 42 1.31 798 1. 35 3. 27 i 778 1. 39 -1. 31 808 1. 29 1. 96 738 .1. 45 1. 92792 1. 36 0. 65 752 1.37 3. 27 768 1. 43 1. 31 752 1. 49 1. 96 782 1. 343. 27 775 1. 35 0. 0 772 1. 40 1. 31 768. 1. 45 0.0 705 1. 38 1. 96772 1. 40 0. 0 812 1. 37. 0. 65 Average percent 767 1. 41; 0. 98 784 1.37 1. 47

. EXAMPLE 6 i In this experirnent 12 .pigs were divided into 3 equal 2.An animal feed composition according to claim 1 in which the sulfa drugis sulfarnethazine.

3. An animal feed composition according to claim 1, in which thesulfadrug is sulfaetnoxypyridazine.

4. An animal feed composition according to claim in which thetetracycline antibiotic is chlortetracycline.

5. An animal feed composition according to claim 4 in which thechl-ortetracycline is present to the extent of groups of 4. They wereindividually Weighed and their weights of each group were averaged andtheresults re corded. From these results given below, it can be notedthat pigs treated with 300 grnsJ ton chlortetracycline, 300 gms./ tonsulfametlrazine,--and 150 gms/ton penicillin exhibited an enhancedgrowth rate. However, such growth rate was slightly less than thatobtained by pigs treated with the preferred combination c5100 gms./tonof chlortetra-cycline, 100 gms/ ton of sulfamethazine. and 50 1. Ananimal feed composition effective in accelerating the growth rate ofanimals which comprises a nutritionally-balanced animal feed containingfrom about 10 to about 300 grams per ton of feed of a tetracyclineantibiotic selected from the group consisting of tetracycline,

chlortetracycline, oxytetracycline; and demethylchlortet- I racycline,from about 10 to about 300 grams per ton ofteed of a sulfa drug selectedfrom the group consisting of sulfamethazine and sulfaethpxypyridazineand from g about 5 to about 150 grams perttSn of feed of penicillinaverage weight calculated. They were then placed in 1 g pens and fed adlibitum a standard, starter pig diet medi- A cated as set forth below.After 42 days the tests were J'ritcrminated and the pigs wereindividually weighed. The

tetracycline is present to the extent'iof about 100 grams about gramsper ton of feed, the sulfamethazine is present to the extent of about100-grams per ton of feed and-the penicillin is present to the extent ofabout 50 grams per ton of feed. 6. A process for increasing growth rateand for im proving feed efliciency in animals which comprises feedingsaid animals a nutritionally-balanced animal feed containing from about10 to about 300 grams per ton of feed of a tetracycline antibioticselected from the group consisting of tetracycline, chlortetracycline,oxytetr-acycline and demethylchlortetracycline, from about 10 to about300 grams per ton of feed of a sulfa drug selected from the groupconsisting of sulamethazine and sul-faethoxypyridazinc, and from about 5to about grams per ton of feed of penicillin.

7. A process according to claim 6 in which the sulfa drug issulfamethazine.

8. A process according to claim 6 in which the sulfa drug issulfaethoxypyridazine.

9. A process according to claim 6 in which the tetra ing the'growth rateof animals which comprises a nutritionally balanced' animal feedcontaining from about 10 to about 300 grams per ton of feed of atetracycline antibiotic selected from the group consisting oftetracycline, chlortetracycline, oxytetracycline, anddemethylchlortetracycline and from about 10 to about 300 grams per. tonof feed of a compound selected from the group consisting ofsulfamethazine and sulfaethoxypyridazine.

12. An animal feed composition according to claim 11 in which thechlortetracycline is present to the extent of about 100 grams per ton offeed and the sulfamethazine is present to the extent of about 100 gramsper ton of feed.

13.; A process for increasing growth rate and for improving feedefficiency in animals which comprises feeding said animals anutritionally-balanced animal feed containing from about 10 toalbout300grams per ton of feed of a tetracycline antibiotic selected from thegroup consisting of tetracycline, chlorotetracycline, oxytetracycline,and demethylchlortetracycline and from about 10 to about 300 grams perton of feed of a compound selected from the group;consisting ofsulfametha zine and sulfaethoxypyridazine. I V

' '14. ,A' process according to claim 13 in which the chlorp'enton offeed and the sulfamethazine is present to the V extent of about '100grams per ton of feed. 7

References Cited by the Examiner Merck Index, seventh edition, 1960,Merck and 00. Rahway, New Jersey, pages 992 and 9.94.

JULIAN S. LEVITT, Primary Examiner.

. FRANK CACCIAPAGLIA; IR., Examiner 11. An animal feed compositionefiective in accelerat Disclaimer 3,185,573.]l[aw J. Harvey, Trenton,NJ. ANIMAL FEED COMPOSITION AND METHOD OF USING SAME. Patent dated May25, 1965.

Disclaimer filed July 10, 1968, by the assignee, American Oyanamz'dCompany.

Hereby enters this disclaimer to claims 11, 12, 13 and 14 of saidpatent.

[Oflicial Gazette December 24, 1968.]

1. AN ANIMAL FEED COMPOSITION EFFECTIVE IN ACCELERATING THE GROWTH RATEOF ANIMALS WHICH COMPRISES A NUTRITIONALLY-BALANCED ANIMAL FEEDCONTAINING FROM ABOUT 10 TO ABOUT 300 GRAMS PER TON OF FEED OF ATETRACYCLINE ANTIBIOTIC SELECTED FORMTHE GROUP CONSISTING OFTETRACYCINE, CHLOROTETRACYCLINE, OXYTETRACYCLINE, ANDDEMETHYLCHLORTETRACYCLINE, FROM ABOUT 10 TO ABOUT 300 GRAMS PER TON OFFEED OF A SULFA DRUG SELECTED FROM THE GROUP CONSISTING OFSULFAMETHAZINE AND SULFAETHOXYPYRIDAZINE AND FROM ABOUT 5 TO ABOUT 150GRAMS PER TON OF FEED OF PENICILLIN.